1. Field of the Invention
Embodiments of the invention relate generally to in-process monitoring systems, and to methods of using such systems. More particularly, disclosed embodiments relate to in-process monitoring systems integrated into a production line and configured to analyze one or more properties of a sample as it is being produced, and methods of using such systems.
2. Description of the Related Art
During the manufacture of pharmaceuticals, fine chemicals, specialty chemicals and the like, a sample of the material is typically removed during production for testing to ensure that the material meets pre-established requirements. For example, a pharmaceutical powder may be tested to ensure that a sufficient amount of an active pharmaceutical ingredient is present. The testing of the material is usually performed “off-line,” which can take hours or even days. By the time the test results are available, production of the material may already have been completed. If the test results do not meet specifications, the whole manufacturing lot must be discarded and must be produced again, which can be expensive, both in terms of time expended and wasted materials. Moreover, because there is a separation between the time of the actual material test and the manufacturing process itself, such test results may not be completely useful in assessing the reason for a failure.
Attempts have been made to design a testing device that may be integrated into the production process so that the material being produced is tested or analyzed while (or at substantially the same time) it is being manufactured. However, such attempts have not been satisfactory, primarily because the resulting devices are inaccurate or introduce additional problems. For example, such devices typically introduce contaminants into the manufactured material (e.g., by the use of compressed shop air), which causes inaccurate test results. Additionally, existing devices are not adequate because they are only capable of performing a subset of the desired tests and the testing of the material is incomplete.